A recent review of health data involving over 130,000 adults with insomnia has raised concerns regarding the long-term use of melatonin supplements. The study, presented at the American Heart Association's Scientific Sessions 2025, found that individuals who took melatonin for a year or more were at a higher risk of developing heart failure, being hospitalized for the condition, and dying from any cause compared to those who did not use the supplement.
Researchers categorized participants based on their melatonin usage, identifying those who had used the supplement for at least 12 months. The analysis revealed that long-term melatonin users had a 90% increased likelihood of experiencing heart failure and were nearly 3.5 times more likely to be hospitalized for the condition. Additionally, the study indicated that these users were almost twice as likely to die from any cause over a five-year period compared to non-users.
Despite these findings, the researchers caution that their study cannot establish a direct causal relationship between melatonin use and these adverse health outcomes. They emphasize the need for further research to explore the implications of melatonin on heart health, especially since the supplement is often perceived as a safe sleep aid.
The study has limitations, including the variability in melatonin regulation across countries and the potential influence of other health factors on the results. Experts have expressed surprise at the frequency of melatonin prescriptions for insomnia, highlighting that the supplement may not be appropriate for chronic use without medical guidance.
As the discussion on melatonin's safety continues, the research underscores the importance of understanding the long-term effects of widely used supplements on cardiovascular health.